title: Myocardial T2* measurements in iron-overloaded thalassemia: An in vivo study to investigate optimal methods of quantification.
abstract: Reproducible and accurate myocardial T2* measurements are required for the quantification of iron in heart tissue in transfused thalassemia. The aim of this study was to determine the best method to measure the myocardial T2* from multi-gradient-echo data acquired both with and without black-blood preparation. Sixteen thalassemia patients from six centers were scanned twice locally, within 1 week, using an optimized bright-blood T2* sequence and then subsequently scanned at the standardization center in London within 4 weeks, using a T2* sequence both with and without black-blood preparation. Different curve-fitting models (monoexponential, truncation, and offset) were applied to the data and the results were compared by means of reproducibility. T2* measurements obtained using the bright- and black-blood techniques. The black-blood data were well fitted by the monoexponential model, which suggests that a more accurate measure of T2* can be obtained by removing the main source of errors in the bright-blood data. For bright-blood data, the offset model appeared to underestimate T2* values substantially and was less reproducible. The truncation model gave rise to more reproducible T2* measurements, which were also closer to the values obtained from the black-blood data.
authors.affiliation: National Heart and Lung Institute, Imperial College London, London, UK.
authors.forename: Taigang
authors.initials: T
authors.lastname: He
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gatehouse
authors.forename: Gillian C
authors.initials: GC
authors.lastname: Smith
authors.forename: Raad H
authors.initials: RH
authors.lastname: Mohiaddin
authors.forename: Dudley J
authors.initials: DJ
authors.lastname: Pennell
authors.forename: David N
authors.initials: DN
authors.lastname: Firmin
mesh_terms: D000328:Adult; D000465:Algorithms; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007501:Iron / Q000032:analysis*; D019190:Iron Overload / Q000175:diagnosis* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013789:Thalassemia / Q000175:diagnosis* / Q000378:metabolism*; D006113:United Kingdom
chemical_list: D007501:Iron